Much Ado About Minimalism

The science and practice of reducing your running shoes

We called her barefoot Bonnie. She showed up at a training run in Earth Shoes and clobbered most of the guys. Then she ditched even that minimal footwear for a summer on the track, beating several of the local elites. At the time, less than two years ago, most people didn't even know it was permitted to race without shoes. Today, we're in a minimalist running craze. The untraditionally shod are, if not everywhere, vociferous enough

that they certainly seem to be. Is there anything actually to it, or is it just noise, inspired by Born to Run, Christopher McDougall's New York Times bestseller about the sandal-wearing ultramarathoners among Mexico's Tarahumara Indians?

Proponents of minimalism speak with the zeal of the recently converted. Opponents spout dire warnings: you'll ruin your arches, step on an HIV-contaminated needle, pound your feet to hamburger. "If you talked to people in podiatry a decade ago, nobody would have said that barefoot activity had any benefit," says Ray McClanahan, a Portland, Ore., podiatrist. "But now, a few people are starting to say it might be good for you."

Away from the hype and the extremes, the minimalist movement is rightly correcting decades of drifting in the other direction when it comes to running shoe design. At its core, minimalism asks the runner to look for the least amount of shoe he or she can safely wear now, and to work toward reducing the amount of shoe necessary through strengthening the foot and improving one's stride. It assumes that running is a natural movement of the body, rather than an unnatural act that requires pads and braces to perform safely. Putting it plainly, the movement embraces the notion that the beefier the shoe, the more a runner's natural stride is inhibited.

After 30 years of making shoes with large amounts of cushy foam and structured stability, shoe companies have gradually gotten into the act -- starting with Nike's Free in 2004. Although most brands have always had some type of lightweight trainer or racer in their line, this spring many manufacturers are offering some type of shoe specifically designed to promote a natural running gait. "More people are shifting toward this type of product, or at least trying it," says Sean Murphy, manager of advanced products engineering and sports research for New Balance. "I think this movement is going to start to affect even the training shoes you see on the wall [in running stores]."

In fact, Murphy says, we may be on the verge of a sea change similar to the one that spawned today's "traditional" shoe in the late 1970s and early '80s.

That movement came out of research inspired by the first running boom, when doctors began wondering about a rash of injuries afflicting the runners of two decades ago. One of those studies, by D. B. Clement, then of the University of British Columbia, tallied injuries to more than 1,600 runners severely injured enough to seek treatment from sports medicine clinics. It found that three of the most common injuries were Achilles tendinitis, metatarsal fractures, and tibial stress syndrome (leading to shin splints and stress fractures of the tibia). At the same time, other labs were discovering from strikeplate tests that runners hit hard in two places: the heel and the forefoot. The conclusion: Shoes needed elevated, cushioned heels to take stress off the Achilles tendon, plus a cushioned forefoot to protect the metatarsals. "At the time, it was all about reducing those stresses," Murphy says. Two other injuries of concern were runner's knee and plantar fasciitis. For them, Murphy says, the conclusion was that prevention meant pronation control. "If you started putting something firm on the medial side [of the shoe]," he says, "[the idea was] that would prevent everything."

Suddenly, many shoes looked more or less alike: lots of heel lift, lots of cushioning, and, for runners who needed stability, beefy protection against excess pronation. The shoes, in other words, that most of us have been wearing for the last 25 years.

GRASSROOTS REVOLUTION

In the early 1980s, running-shoe design was reinvented by the research labs. Today's revolution is more grassroots. And rather than starting with the traditional running community, it's working its way backward, from extreme minimalism enthusiasts into mainstream running. (The majority of highly competitive runners have always done some of their training in low-to-the-ground trainers and racing flats, but until now, they were dismissed as simply being biologically gifted.)

Minimalist runners have a number of complaints about modern shoes. They argue that the more material added under the foot -- foam, rubber, plastic, air bags, gel packets -- the less a runner's feet can "feel" the ground and the less a runner can utilize the afferent feedback gained from the foot-ground interaction. "It's like a gymnast landing on a mat that's too soft," says Michael Sandler, who coaches barefoot running in Boulder, Colo. "Or like trying to play the piano in heavily cushioned gloves." The need to make firm, fully controlled contact with the ground, he argues, means that softer heels require you to come down harder than you would in less cushioned footwear.

Portland podiatrist McClanahan agrees. In addition to heel lift, McClanahan has two main beefs with traditional shoe design. One is the narrow toe box, which he believes pinches toes too close together. The other is "toe spring," in which shoes turn upward at the toes by as much as 30 degrees.

Toe spring, he says, appears to have been designed to help runners roll more efficiently forward, off their toes -- a possible boon back when midsoles were stiffer than they are today. But he thinks it's outlived its usefulness. The spring is so strong, he says, that a study of Boston Marathon participants found that, standing neutrally, most runners' toes never even touched the ground. "Only one in 100 had any toe imprint," he says. "You're never in neutral position."

Whatever the cause, everyone agrees that shoes radically change the way most people run. Just to start with, barefoot runners don't heel strike. "It hurts," Sandler says. Instead, unshod runners or those wearing very minimalist footwear will tend to land on their midfoot, at the ball of the foot.

"If you run with a shoe," says New Balance's Murphy, "about 80 percent of the population lands with a heel strike and 20 percent on the middle or forefoot. [But] when people take their shoes off, they change the way they run."

BUT WILL IT MAKE ME FASTER?

For serious competitors, most of this is meaningless if we don't know its effect on performance. Years ago, South Africa's Zola Budd ran world-class times barefoot. And my club's Barefoot Bonnie could easily produce a sub-18:00 5K. But were they fast because they ran barefoot? Or would they have been fast, regardless, and being fast and efficient allowed them to run barefoot?

Nobody's sure. "There are good arguments [why barefoot is faster]" says Benno Nigg, a professor of biomechanics at the University of Calgary, "but it's just anecdotal. Your [foot] muscles are becoming stronger, so you should be able to have better performance. It makes sense, but nobody has proven it."

But evidence is starting to come in.

A 2007 study in the Journal of Strength Conditioning Research showed that foot motion and performance are definitely linked. Hiroshi Hasegawa and colleagues from Ryukoku University in Kyoto, Japan, videotaped 283 elite runners at the 15K mark of the 2004 Sapporo International Half Marathon. Even among the elites, they discovered, nearly three-quarters landed on their heels. But the fraction was reduced to 62 percent among those running faster than 4:55 miles.

The front of the pack also had reduced contact times -- the interval in which the foot touches the ground, each stride. And heel strikers' contact times were nearly 10 percent longer than forefoot or midfoot strikers', again suggesting that heel striking might slow you down and that barefoot-mimicking minimalist footwear might speed you up. It certainly fits barefoot-running theory, which argues that the barefoot style not only puts you up on your midfoot, but leads you to run with a lighter, springier stride, translating to reduced contact time.

But again, this isn't concrete proof. Perhaps landing on the forefoot is simply a side effect of going faster.

Jack Daniels, author of Daniels' Running Formula, is a coach and exercise physiologist who sometimes runs barefoot on tracks near his Flagstaff, Ariz., home. Some years ago, he conducted studies (never published) on the effects of footwear on oxygen demand. The results were limited but they too suggest that minimal footwear is better.

Much of the work was designed simply to test the effect of shoe weight on performance. (He and his colleagues found a 1 percent increase in aerobic demand for each 100 grams of weight per shoe.)

But they also found that skimpier designs increase performance ... to a point. After that, cutting down the shoe not only failed to reduce the aerobic "cost," but minimalist shoes actually became less efficient.

"Presumably," Daniels says, "[that's] because to get real light you sacrifice shock-absorbing and energy-return characteristics." (On the track, however, they found improvements all the way down to the most minimal shoes they could devise. Apparently, the nice, resilient surface of a well-built track gave their test subjects all the shock absorption and energy return they needed.)

And what of the unparalleled East African runners, who reputedly develop their perfect strides running barefoot to school? Why are shoes one of the first purchases African runners make once they can afford them?

"[In Kenya,] only children are running barefoot, and indeed only because they don't have the money to buy shoes," Pieter Langerhorst, husband and agent of Kenyan-born worldrecord holder Lornah Kiplagat, said by email. But, he adds, that doesn't mean the top runners have totally abandoned barefoot running. After track workouts, they often take barefoot cooldowns on the grass of the infield.

"This keeps the muscles in the feet also eager," Langerhorst wrote in his Dutch-flavored English. Many top Western runners also run barefoot strides for similar reasons, even if they didn't grow up unshod.

Or consider Ethiopia's Abebe Bikila, who ran b arefoot through the streets of Rome in the 1960 Olympics, setting a world-record 2:15:17 marathon. Score one for barefoot running. But four years later he was back, this time in shoes, albeit a pair of Pumas that, typical of the era, were lightweight and minimally constructed. The result, another world record, 3 minutes faster: 2:12:12. Was he simply in better shape? Or was it the shoes?

Sandler thinks it's because all those years of running barefoot has trained African runners to "feel" the ground with each stride. With that background, super-lightweight shoes that still allow them to retain most of that feel become an asset. The argument is similar to that put forth by Nike when it introduced the Free, one of the first formal corporate forays into minimalism. After years of studying barefoot runners, Nike launched them in 2004 as a training tool, one that could teach your body a more barefoot style, but with a stern warning that you don't have to, indeed should not, run in them every day

New Balance's Murphy agrees that too little shoe can hold you back, especially on trails. That's because, however naturally these shoes encourage you to run, you're going to feel every lump. "You're more fearful of that next sharp rock," he says. "You won't put as much force on the next step."

In addition to possible skin damage, one must consider the hardness of the surface. Kenyan kids don't run on concrete sidewalks, but soft dirt roads and trails with a similar under-foot feel as Daniels' cushioned track.

LESS VS. TOO LITTLE

In other words, less is more ... but only to a point. And nobody's really sure yet where that point lies. Most likely, it's an individual decision, ranging from Bonnie in her bare feet to someone whose Brooks Beasts are doing their job perfectly and who has every reason not to change.

Most runners are not going to want to go all the way to barefoot running, or to barefootsimulating shoes like the Vibram FiveFingers or Terra Plana EVO Barefoot. For them, minimalism will mean something less radical.

Shoe companies are scr ambling to get into the act of producing scientifically designed "moderate" alternatives.

First, though, they have to figure out precisely how shoe design affects running style.

Obviously, it's not the simple fact of having something on your feet that makes the difference. Runners using the Vibram FiveFingers run barefoot style, even though it is technically a shoe (albeit a very stripped-down one). Presumably, the difference lies in the thickness of the cushioning and the geometry of the heel. There would seem to be a point at which, with reduced cushion and heel design, a standard shoe begins to behave more like a FiveFingers. "If you start with a thick shoe and slowly whittle down," Murphy asks, "at what point does the person start to run like they're barefoot?

We've completed those studies," he adds, "and come up with some pretty solid lines of thinking on how you make the foot work as naturally as possible, and at the same time protect [it] from the elements." Expect to see the results in early 2011, joining a slew of new designs that have emerged in recent years from companies old and new to meet the minimalist demand.

Even with today's options, the choice is far more complex than "to bare or not to bare." "People are trying to separate this into 'no shoes' [vs.] 'motion-control shoes,' whereas there is a whole bunch in between," says Mark Plaatjes, a physical therapist and co-owner of Colorado's Boulder Running Company.

"I'm convinced that going in the direction of minimalism, if you do it responsibly, will be a healthy thing for most people," adds McClanahan. "[But] not everybody."

Who shouldn't do it? Diabetics, to begin with. "They don't feel their feet," McClanahan says. "They're going to damage their joints." Also on McClanahan's don't-try-it list are people with rheumatoid arthritis or otherwise abnormal feet. Sandler includes people with bones that didn't heal properly from a break.

Plaatjes, the 1993 world champion in the marathon, believes the no-go list is a bit larger than that. "There are people who will absolutely hurt themselves, regardless of how easily they go into [minimalist] running," he says. "It's an issue of ligament laxity and biomechanics, and they just can't do it."

Plaatjes believes there's only one way to figure out which group you belong in. "You really have to have somebody look at you and give an opinion as to whether this is really an option for you," he says. And in doing this, he adds, don't automatically presume that running stores are out to sell you the beefiest shoe they can convince you to buy.

"I don't make more profit from a stability shoe," he says. "If you come into my store, I have absolutely no reason, other than to put you in the right shoe, to put you in a stability shoe or a minimalist shoe."

Finally, if you do decide to shift to a more minimalist shoe, caution should be your watchword. While there's not yet a lot of coaching experience with minimalism, a standard coaching rule is not to jump into anything too quickly.

That's particularly true for those contemplating major changes. Even the extremists started slow: "I went out 100 yards the first day," says barefoot coach Sandler, "then walked home and iced my feet for a couple of days. Then I did a couple hundred yards and iced for a couple of days."

"It took me a year to get fully accustomed to my Vibram FiveFingers," adds McClanahan.

So, start easy, both in how far you move away from the shoes you've been running in, and how long you spend in more minimal footwear.

You also need to pay attention to your feet. Don't just throw on the new shoes and head out the door, Murphy says. "Do it with a great deal of awareness. You're going to use muscles you haven't used for a while." In particular, he says, minimalist shoes will probably give you sore calves, and possibly soreness in little-used muscles of your feet. "That's not necessarily a bad thing. It just means you're working that part of your body a little differently."

Working new muscles to strengthen them is what we do as runners. Moving to a lesssupportive shoe will likely reveal core and hip weakness as well, and require work to strengthen these. Ultimately, the minimalist goal is to run better -- more naturally, more efficiently, with less impact -- making us less prone to injury, so we can run longer, and faster. It's not about the shoes.